The calls took place at their Mar-a-Lago estate in Florida on Sunday, where Mr. and Mrs. Trump fielded questions from children dialing into NORAD’s phone line looking to see where Santa was on his journey.

NORAD offers an annual tracker for those interested in following Mr. Claus’ trek before Christmas Day with live updates by phone, Facebook, Twitter and email. If you call 877-HI-NORAD, someone will give you an update.

U.S. President Donald Trump and First Lady Melania Trump participate in NORAD (North American Aerospace Defense Command) Santa Tracker phone calls with children at Mar-a-Lago estate in Palm Beach, Florida, U.S., December 24, 2017.

Carlos Barria / REUTERS

The president was heard telling one child on the phone to come visit in Washington and see him in the Oval Office. Another, from Virginia, was heard telling the president he wanted building blocks.

“Oh, building blocks, that’s what I always liked too. I predict that Santa will bring you building blocks, so many you can’t use them all,” Mr. Trump replied.

First Lady Melania Trump tweeted ahead of the call, saying she looked forward to “helping kids track Santa today with @NoradSanta!” She also wished a “very Merry Christmas Eve” to her followers.